--- a/src/callbacks.c
+++ b/src/callbacks.c
@@ -13,6 +13,9 @@
 #include "support.h"
 
 
+GtkWidget        *gcolor2;
+GtkWidget        *menu;
+GdkColor          colorvalue;
 GtkWidget        *savedialog;
 gchar            *colorname;
 static GtkWidget *aboutdialog = NULL;
--- a/src/callbacks.h
+++ b/src/callbacks.h
@@ -42,9 +42,9 @@
                            "\302\267 Usability / user interface enhancements\n" \
                            "\302\267 Code cleanup"
 
-GtkWidget *gcolor2;
-GtkWidget *menu;
-GdkColor   colorvalue;
+extern GtkWidget *gcolor2;
+extern GtkWidget *menu;
+extern GdkColor   colorvalue;
 
 enum
 {
